Check if game is running thru Steam

[betazero]

I am going to be selling my game on Steam but they do not allow external links like for itch.io or Patreon. Is there an if statement that I can use to remove these things IF the game is running thru Steam? Sorry if this is a Nuub question but I would prefer not having two versions of the game. The Steam Achievements can be there and will just do nothing if not connected to Steam so I am hoping I can do the same with certain elements.

Thanks in advance,
Russell

[Imperf3kt]

Put a link / invite to a discord server in the game and within that advertise your other services including patreon etc.
This has the benefit of allowing you to link to steam as well, so players from itch.io etc can find you on Steam too.

Its only other payment services that steam refuses to allow you to put in your game, you're perfectly fine adding a discord server invite and steam can't control what you do in that discord.